Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D19/00—Arrangements of controlling devices
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
  • C21C1/00—Refining of pig-iron; Cast iron
  • C21C1/06—Constructional features of mixers for pig-iron
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D21/00—Arrangements of monitoring devices; Arrangements of safety devices
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D21/00—Arrangements of monitoring devices; Arrangements of safety devices
  • F27D21/0014—Devices for monitoring temperature
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D27/00—Stirring devices for molten material
  • F27D27/005—Pumps
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D9/00—Cooling of furnaces or of charges therein
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D9/00—Cooling of furnaces or of charges therein
  • F27D2009/0002—Cooling of furnaces
  • F27D2009/0005—Cooling of furnaces the cooling medium being a gas
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D19/00—Arrangements of controlling devices
  • F27D2019/0003—Monitoring the temperature or a characteristic of the charge and using it as a controlling value
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D21/00—Arrangements of monitoring devices; Arrangements of safety devices
  • F27D2021/0057—Security or safety devices, e.g. for protection against heat, noise, pollution or too much duress; Ergonomic aspects
  • F27D2021/0085—Security or safety devices, e.g. for protection against heat, noise, pollution or too much duress; Ergonomic aspects against molten metal, e.g. leakage or splashes

Definitions

• the present invention relates to pumps used to circulate material in non-ferrous molten metal furnaces and, more specifically, to the location and operation of electromagnetic or permanent magnet-based molten metal pumps.
• Magnetic pumps are sometimes used to induce eddy currents in the metal in order to induce such flow or agitation.
• Electromagnetic devices are used in some known pumps, and permanent magnets are used in other such pumps.
• Such pumps are typically attached to the outside of a side wall of a furnace, and the molten metal may be piped into and around the pump structure (as in published U.S. patent application publication numbers 201 1/0248432 and 2010/0244338, which are both incorporated herein by reference). This means that molten metal is moved outside the furnace, elevating the likelihood of an uncontained leak from such pumps and associated structures.
• the present invention solves the problems described above, and provides other benefits by positioning a magnetic pump, which may be an electromagnetic or permanent magnet based pump, at the entrance to a side well of the furnace and in a pump well with a long, relatively thin side wall that wraps around a significant fraction of the circumference of the pump.
• the long, thin side wall of the pump well and significant wrap angle around the pump well facilitates creation of a strong eddy current based flow field in the molten material with better magnetic coupling, thereby enhancing the effectiveness of the pump.
• the risk of breach of the relatively thin pump well wall is acceptable because breach of the well wall and flow of molten metal into the well will not result in spillage of metal outside the furnace.
• the well can be monitored for any such breach so that the pump can be lifted out of the well to protect it from contact with the molten metal in the event of such a breach.
• Figure 1 is a perspective view of a pump of this invention in a well in a metal furnace.
• Figure 2 is an elevation view, in section of the installed pump shown in Figure 1.
• Figure 3 is a schematic plan view of a furnace and pump of this invention.
• Figure 4 is a schematicized side view, partially in section, of another embodiment of the pump of this invention in a well in a metal furnace.
• Figure 5 is a schematic plan view of a furnace and pump according to another embodiment.
• Figures 6-7 are isometric views of a lift system according to an embodiment.
• Figure 8 is a schematic plan view of a furnace and pump according to another embodiment.
• the present invention solves the problems described above by positioning a magnetic pump 10, which may be an electromagnetic or permanent magnet based pump, in a well 12 located entirely inside the exterior wall 14 of a metal melting furnace 16 and near the entrance 22 to a side well 18 of furnace 16. Certain kinds of scrap may be added in the side well 18, and the extra turbulence in the molten metal generated by the pump 10 quickly submerges and melts the scrap. Agitation in side well 18 also agitates the metal in the main hearth area 20 of furnace 16.
• a magnetic pump 10 which may be an electromagnetic or permanent magnet based pump
• the pump 10 illustrated in Figures 1-2 is a permanent pump that is driven by a motor 24 coupled to a gear box 26.
• the motor 24 may be electrically powered with alternating current or direct current, hydraulically powered or otherwise operated to provide rotational force.
• the gear box 26, which may be interposed between the motor 24 and a vertical shaft (not visible in Figures 1-3), reduces the relatively high rotational speed of the motor 24. This provides a lower rotational speed for rotating an arrangement of one or more permanent magnets (also not visible in Figures 1-2) that rotate just inside the inner wall 28 of the cooling jacket 30 through which air, nitrogen or other suitable cooling medium is circulated through inlet 34.
• Cooling jacket 30 is adjacent to a relatively thin refractory wall 32 of the furnace 16 well 12. This cooling maintains a thermal freeze plane. This reduces the likelihood that the aluminum or other molten metal will dissolve holes in the wall 32 of the well 12. If such holes nevertheless form, because the metal is still retained within the furnace, the consequences typically will be less severe than those potentially associated with breach of an exterior wall of a furnace.
• FIG. 8 illustrates a linear induction motor 200 that may be positioned in a well 212 located entirely inside a metal melting furnace 216 and near a side well 218 of furnace 116.
• the pump arrangement of this invention provides an open channel flow system to move molten metal due to the eddy current based flow field created by the magnetic pump, thereby agitating the metal and contributing to maintenance of homogeneous temperatures within the metal.
• the arrangement of the pump within a relatively thin wall of a well within the furnace minimizes the distance between the moving metal and the magnet, thus facilitating creation of strong eddy currents in the molten material, thereby enhancing the effectiveness of the pump.
• the magnetic pump is positioned within the furnace such that significant linear vortexes are created within the metal.
• the magnet may be positioned and configured to generate eddy current based flow field for the molten metal positioned within approximately half the thickness of the thin wall of the well (closest to the pump) and force a linear flow along this portion of the metal closest to the magnet.
• the other approximately half of the molten metal within the thin wall flows in a sympathetic, tortuous path that in turn generates a strong linear vortex throughout the depth of the well.
• FIG. 4 depicts another embodiment of a magnetic pump in a well of this invention.
• Pump 40 is a permanent magnetic based pump and includes a motor/gearbox 42 that drives a shaft 44 that rotates permanent magnets 46 within a well 48 positioned in a molten metal furnace 50 having a main hearth area 52 and a side well 54. Cooling medium indicated by arrows 56 is blown into the well 48 by a blower 58 and exits through port 60.
• a controller 70 controls motor/gearbox 42 and blower 58.
• a signal from detector 62 can activate a lift system to lift the pump out of the well.
• the lift system includes a hoist (not shown) attached to chain 64 or cable attached to motor/gearbox 42 and capable of lifting pump 40 out of the well 48 to protect it from damage.
• Figures 6-7 illustrate another non-limiting embodiment of a lift system 300 configured to hoist a pump (such as pump 400) out the well in the event of a breach.
• the lift system 300 illustrated in Figures 6-7 includes a cart 301 having a plurality of wheels 303.
• the cart 301 is configured to traverse along a set of rails 302 to move the pump 400 away from the furnace.
• Detector 62 can be a thermocouple or other temperature detector for detecting the temperature within the well at the location of the detector.
• detector 62 is a duplex type K thermocouple with an open-ended protection tube and ceramic bead insulators, although any suitable thermocouple or other temperature detector may be used.
• Detector 62 could, alternatively, be a detector capable of detecting the presence of molten metal in the well by other means. It can also be any other detector adapted to directly or indirectly detect a condition, such as elevated
• US2008 5432888 1 7 Attorney Docket No: 62304-898050 temperature, cessation of air flow, conductivity which indicates the presence of molten metal, change in moisture content of the air or any other parameter or condition capable of being monitored.
• more than one detector 62 is used and in some cases, more than one type of detector is used.
• a thermocouple or other temperature detector is used, as well as a detector capable of detecting the presence of molten metal by another means, such as by measuring conductivity with a conduction probe.
• one of the detectors may be part of a Warrick® conductivity system circuit that has liquid level sensing capabilities such as, but not limited to, Warrick® Series 16M controls.
• thermocouple element may detect temperature from any suitable location, for example but not limited to, approximately 1 ⁇ 2" from the bottom of the well 48.
• a conductivity system such as but not limited to a Warrick relay reference probe, may be connected directly to the well wall to detect a breach by sensing conductivity associated with any metal infiltration.
• a programmable logic controller or suitable processer can receive and interpret the signal from detector 62 and initiate any suitable action.
• the PLC can sound or display an alarm so that a furnace operator can determine whether to lift pump 40 out of the well 48, or take any other appropriate action.
• the PLC can activate a lift apparatus to lift pump 40 out of well 48.
• Signals from detector 62 and/or the PLC could also be used to automatically or through operator action otherwise control the furnace by, for instance, stopping rotation of the magnets 46 or adjusting the speed of rotation by
• US2008 5432888 1 8 Attorney Docket No: 62304-898050 adjusting operation of motor/gearbox 42, adjust cooling airflow 56 by adjusting operation of blower 58, or changing heat input to the main hearth 52 or some other portion of the furnace 50.
• FIG. 5 is another plan view depicting an embodiment of a permanent magnet pump in a well.
• a magnetic pump 100 is positioned in a well 1 12 that is located entirely inside a metal melting furnace 116 and near a side well 1 18 of furnace 116.
• Certain kinds of scrap (such as, without limitation, light gauge, clips, chips, or post-consumer based bale scrap) may be added in the side well 1 18 and/or side well 122 and the extra turbulence in the molten metal generated by the pump 100 quickly submerges and melts the scrap.
• Agitation in side well 112 also agitates the metal in other areas of the furnace and circulates the metal between the main hearth area 120, the side well 118, and the side well 1 12 of the furnace 1 16.
• submerged ports allow metal to flow between side well 112 and hearth area 120 and between side well 1 12 and side well 118.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Waste-Gas Treatment And Other Accessory Devices For Furnaces (AREA)
• Vertical, Hearth, Or Arc Furnaces (AREA)
• Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

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Citations (6)

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• 2014
  • 2014-03-10 JP JP2016500950A patent/JP6338650B2/ja active Active
  • 2014-03-10 KR KR1020157028078A patent/KR101766105B1/ko active IP Right Grant
  • 2014-03-10 US US14/202,123 patent/US9395120B2/en active Active
  • 2014-03-10 PL PL14718213T patent/PL2825678T3/pl unknown
  • 2014-03-10 US US14/202,090 patent/US9404687B2/en active Active
  • 2014-03-10 WO PCT/US2014/022364 patent/WO2014164413A1/en active Application Filing
  • 2014-03-10 EP EP14718213.3A patent/EP2825678B1/en active Active
  • 2014-03-10 HU HUE14718213A patent/HUE033155T2/en unknown
• 2016
  • 2016-06-21 US US15/187,905 patent/US10371449B2/en active Active

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